I haven't heard a great argument explaining why human life is objectively more valuable than animal life. The most common argument I hear, even from otherwise thoughtful people I know, is something along the lines of "because one is a <i>human</i> and the other is an <i>animal</i>, duh!" but I don't consider that to be a persuasive argument.<p>Is it because we value organisms that are "smarter"? If that's the case, is the life of a person with a high IQ objectively more valuable than the life of a person with a lower IQ?<p>Is it because we think animals aren't capable of feeling fear, pain, anxiety, and love?<p>Is it a tribalism thing? If we assume that elephants, chimps, or whales are capable of some level of ethical reasoning, are they expected to also value human life higher than their own, or would that be considered immoral because they're "species traitors"? Is the "moral" expectation that a chimp would value chimp life higher, a dog would value dog life higher, and a human would value human life higher?